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Objective:To understand the epidemiological characteristics and pathogenic spectrum of influenza-like illnesses in Tianjin Children′s Hospital from October 2020 to March 2021, and to provide reference for the prevention, control and clinical diagnosis and treatment of influenza-like illnesses.Methods:A total of 520 throat swabs samples were collected from patients with influenza-like illnesses in sentinel hospitals. Thirty respiratory tract pathogens were detected by real-time fluorescence quantitative PCR. The results were statistically analyzed by descriptive epidemiological methods.Results:Among the 520 samples, 239 were positive for 16 respiratory pathogens with a positive rate of 45.96%. The top three pathogens were respiratory syncytial virus (9.62%, 50/520), rhinovirus (9.62%, 50/520) and cytomegalovirus (5.96%, 31/520). The positive rate of respiratory pathogens was 49.67% in males and 40.91% in females and the difference between males and females was statistically significant (χ 2=3.919, P<0.05). There were significant differences in the positive rates among three age groups (χ 2=6.182, P<0.05) with the highest positive rate in the <2 years old group (52.91%, 91/172) and the lowest rate in the >4 years old group (38.10%, 40/105). There were significant differences in the positive rates detected in different months (χ 2=15.358, P<0.05) and the highest detection rate was in December (58.00%, 58/100), followed by those in November (52.50%, 42/80) and January (47.50%, 38/80). The multiple infection rate was 21.76% (52/239) and most of the multiple infections were caused by rhinovirus and other pathogens (48.08%, 25/52). Conclusions:Respiratory syncytial virus, rhinovirus and cytomegalovirus were the predonimant pathogens responsible for influenza-like illnesses in Tianjin Children′s Hospital from October 2020 to March 2021. Multiple infections were common and children under 2 years old were more susceptible. The detection rate of respiratory pathogens varied in different months. It was necessary to strengthen the surveillance and research on those respiratory pathogens in order to provide scientific data for the prevention and control of respiratory diseases in children.
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Objective:To study the characteristics and influence factors of laboratory test results of confirmed COVID-19 cases in Tianjin.Methods:Sample collection was conducted based on the standard operating procedure. Tianlong automatic magnetic bead nucleic acid extraction reagent was used for RNA extraction. Real-time RT-PCR was performed using four approved COVID-19 nucleic acid detection kits. Related epidemiological data of the cases were collected. One-way analysis of variance and non-parametric test for inter-group differences analysis were conducted using SPSS25.0 software.Results:A total of 162 PCR tests were completed for novel coronavirus nucleic acid detection in 123 confirmed COVID-19 cases. Eleven PCR results were positive for a single target gene and 10 of which were positive for nucleocapsid protein (N) gene. Nineteen cases were tested with two kinds of nucleic acid detection kits and the results of different detection kits were different. Different types of samples were collected form 13 cases for nucleic acid detection and the results showed that the Ct value of sputum sample was lower than that of throat swab sample. No significant difference in Ct values of throat swab samples was observed among patients with different clinical symptoms ( PCt-N=0.797, PCt-ORF1a/b=0.551). The 123 cases were divided into different groups according to the time interval between the onset date and the date of the first positive detection of viral nucleic acid. No significant difference in Ct values of throat swab samples was observed among different time interval groups ( PCt-N=0.373, PCt-ORF1a/b=0.058). Conclusions:Sputum samples were better than upper respiratory tract samples for viral nucleic acid detection. The sensitivity of N gene detection was higher, but re-sampling was needed when the result was positive for the single target N gene. Appropriate detection kits should be selected according to the actual needs, and samples should be collected at multiple time points, in multiple types and form multiple sites for detection.
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Objective To evaluate the immune responses and protection against human metapneu-movirus ( hMPV) conveyed by influenza virus vectors carrying multiple epitope antigens of hMPV. Methods Two recombinant influenza viruses ( rFLU/hMPV/B and rFLU/hMPV/CTL+Th ) carrying hMPV multi-epitope gene segments in NS gene were generated by reverse genetic techniques of eight-plasmid system. BALB/c mice were immunized intranasally with rFLU/hMPV/B and rFLU/hMPV/CTL+Th twice at a two-week interval. Virus-specific antibody titers and splenocyte cytokines were detected two weeks after the boost immunization. Viral loads in lung tissues and turbinates were detected with digital PCR after the immunized mice were challenged with hMPV and influenza virus. Moreover, HE staining was used to observe lung inju-ries. Results Specific antibodies against both the influenza virus and hMPV were induced in mice immu-nized intranasally with rFLU/hMPV/B, while the influenza virus-specific antibody response and hMPV-spe-cific cytotoxic lymphocyte response ( significant IFN-γ secretion ) were detected in mice immunized with rFLU/hMPV/CTL+Th. Additionally, balanced Th1/Th2 responses were elicited by rFLU/hMPV/B and rFLU/hMPV/CTL+Th. Both rFLU/hMPV/B and rFLU/hMPV/CTL+Th conveyed effective protection against subsequent influenza virus and hMPV challenges with significantly alleviated histopathological dama-ges and reduced viral loads. Conclusions Both rFLU/hMPV/B and rFLU/hMPV/CTL+Th can induce spe-cific humoral immune response against hMPV and/or the influenza virus. Moreover, rFLU/hMPV/CTL+Th can also elicit hMPV-specific CTL immune response. These two recombinant strains can also protect BALB/c mice from the challenges with hMPV and influenza virus, suggesting that they are promising vaccine candi-dates.
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Objective To investigate and analysis the epidemiological characteristics of a cluster epidemic of COIVD-19 in a collective workplace in Tianjin, evduate the prevention and control measures based on limited evidence and experience in early period of COVID-19 epidemic. Methods Descriptive research method was used to describe the distribution and other epidemiological characteristics of the cluster cases of COVID-19. Results Since the onset of the first index case on January 15, ten confirmed COVID-19 cases had occurred in the workplace, and the epidemic had spread from the workplace to 4 families, infecting 7 family members. The median age of 17 cases was 55 (19-79) years. All the 10 employee cases were males, and in 7 family cases, 3 were males and 4 were females. Of the employee cases, 8 worked in CW workshop and 2 worked in administrative office building. The median exposure-onset interval of all the cases was 4 (0-12) days, and the median exposure-onset interval was 4.5 days in the employee cases and 4 days in the family cases. The median onset-medical care seeking interval was 4 days in the non-isolated cases, 2.5 days in the cases with home isolation after onset, and 0.5 day in the cases with home isolation before onset. Conclusion The clustering of COVID-19 cases was observed in this workplace in Tianjin, which affected 4 families. In the early stage of the epidemic, accurate and rapid blocking and control measures can completely prevent the large-scale spread of COVID-19.
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Objective@#To evaluate the immune responses and protection against human metapneumovirus (hMPV) conveyed by influenza virus vectors carrying multiple epitope antigens of hMPV.@*Methods@#Two recombinant influenza viruses (rFLU/hMPV/B and rFLU/hMPV/CTL+ Th) carrying hMPV multi-epitope gene segments in NS gene were generated by reverse genetic techniques of eight-plasmid system. BALB/c mice were immunized intranasally with rFLU/hMPV/B and rFLU/hMPV/CTL+ Th twice at a two-week interval. Virus-specific antibody titers and splenocyte cytokines were detected two weeks after the boost immunization. Viral loads in lung tissues and turbinates were detected with digital PCR after the immunized mice were challenged with hMPV and influenza virus. Moreover, HE staining was used to observe lung injuries.@*Results@#Specific antibodies against both the influenza virus and hMPV were induced in mice immunized intranasally with rFLU/hMPV/B, while the influenza virus-specific antibody response and hMPV-specific cytotoxic lymphocyte response (significant IFN-γ secretion) were detected in mice immunized with rFLU/hMPV/CTL+ Th. Additionally, balanced Th1/Th2 responses were elicited by rFLU/hMPV/B and rFLU/hMPV/CTL+ Th. Both rFLU/hMPV/B and rFLU/hMPV/CTL+ Th conveyed effective protection against subsequent influenza virus and hMPV challenges with significantly alleviated histopathological damages and reduced viral loads.@*Conclusions@#Both rFLU/hMPV/B and rFLU/hMPV/CTL+ Th can induce specific humoral immune response against hMPV and/or the influenza virus. Moreover, rFLU/hMPV/CTL+ Th can also elicit hMPV-specific CTL immune response. These two recombinant strains can also protect BALB/c mice from the challenges with hMPV and influenza virus, suggesting that they are promising vaccine candidates.
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Objective To construct and rescue recombinant influenza virus strains expressing hu-man metapneumovirus ( hMPV) epitopes. -ethods B cell, CTL and Th epitopes predicted by bioinformat-ics software were coupled together in different combinations. These different array genes were inserted into the NS1 gene of influenza virus strain A/PR/8/34 ( PR8 ) , respectively. Recombinant PR8 influenza virus vectors expressing different hMPV antigenic epitopes were rescued by reverse genetics using eight-plasmid system. Sequencing analysis was conducted to verify whether the rescued viruses carried the chimeric hMPV epitopes. Hemagglutination ( HA) titers, half tissue culture infection dose ( TCID50 ) and growth curves were detected. Results Interval sequences GPGPG and KK were introduced into hMPV epitope combinations to construct multi-epitope antigens (MEA). These MEA were inserted into the PR8 NS gene, respectively. Using 8 plasmid system, three recombinant influenza virus strains were rescued successfully. After cultured for three passages in Madin-Darby canine kidney ( MDCK) cells and one in eggs, these three recombinant strains could proliferate steadily. Whole genome sequencing verified that the three recombinant strains car-ried the chimeric MEA sequences, named as rFLU/hMPV/B, rFLU/hMPV/CTL-Th and rFLU/hMPV/B-Th. HA titers of the recombinant strains were 128, 128 and 256 using turkey erythrocyte, respectively. Their TCID50 were 107. 0/ml, 106. 8/ml and 107. 0/ml, respectively. Growth curve tests also verified that the recombinant strains could proliferate steadily in MDCK cells. Conclusions Three recombinant influenza vi-rus vector strains carrying the B cell, CTL and Th epitopes of hMPV were rescued successfully. This study lays the foundation for further evaluation of the immune effects of these recombinant viruses and their poten-tial application value in vaccine development.
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Clinical data of 12 cases of Trousseau syndrome with cerebral infarction as initial presentation admitted in the neurology department of the Fourth Affiliated Hospital of Hebei Medical University from December 2011 to December 2017 were retrospectively analyzed.Of the 12 patients,4 cases had risk factors for cerebral infarction and 8 ones had no risk factors.There were 2 patients with 1 lesion and 10 patients with two or more lesions in brain imaging.The infarction lesions of 9 patients were located in 2 or more arterial blood supply areas.Ten patients showed an elevated plasma D-dimer level,5 had elevated fibrinogen level,7 showed increased blood platelet count and 8 had increased homocysteine level.Ten cases were confirmed by pathology,2 cases by clinic and imaging diagnosis.The study suggests that multiple lesions with several cerebral arteries involved,high plasma D-dimer and fibrinogen levels may be the clinical characteristics of Trousseau syndrome with initial presentation as acute ischemic stroke and lacking of risk factors.The hypercoagulation state may be the important pathogenesis of this disorder.
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Objective To observe the differences of metabolite ratios among mild cognitive impairment (MCI),Alzheimer’s disease (AD) and normal cognitive state (NC)patients in the hippocampus.Methods According to the clinical features,patients were divided into three groups:MCI group (n=30),AD group (n=28)and NC group (n=30).All the patients were examined by 1 H MRS and compared the ratios of NAA/Cr,Ins/Cr,NAA/Ins,Cho/Cr of both the left and right side of the hippocampus.Results The NAA/Cr in MCI group and AD group were much lower than that in NC group (P <0.05).The Ins/Cr and NAA/Ins in MCI group and AD group showed significant differences compared with NC group (P <0.05).On Ins/Cr and NAA/Ins of the left side,there were significant differences among three groups (P <0.05).Conclusion 1 H MRS as a non-invasive diagnostic technique has higher sensitivity in the early diagnosis and differential diagnosis between MCI and AD patients.
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Objective To evaluate the immune response triggered by an in-house constructed hu-man metapneumovirus multi-epitope antigen ( MEA) in a mouse model .Methods Female SPF BALB/c mice at age 4-6 weeks were used in the study and divided into 7 groups.Mice in the five groups including MEA+oligodeoxynucleotides containing CpG motifs ( CpG ODN) intraperitoneal injection ( i.p.) treatment group, MEA+Alum i.p.treatment group, MEA+Alum+CpG ODN i.p.treatment group, MEA+CpG ODN intranasal (i.n.) treatment group and MEA+Alum+CpG ODN i.n.treatment group were immunized three times on days 0, 14 and 21, and those in the other experimental group were immunized intramuscularly with MEA+Quickantibody5W on days 0 and 21.A control group without treatment was set up accordingly .All mice were sacrificed two weeks after the last immunization .Antibodies including IgG , IgG1, IgG2a and IgA in serum samples were detected by ELISA .MTS assay was performed to analyze the proliferation of lympho-cytes.The cytotoxicity of cytotoxic T lymphocytes (CTL) was measured by LDH assay.Flow cytometry was used to detect T lymphocyte subsets .The cytokines secreted by T helper cells ( Th1 and Th2) were analyzed with Bio-Rad Liquid Chips.Results High titers of IgG, IgG1 and IgG2a antibodies were produced in MEA treated mice except for those in intranasal treatment groups .Serum samples from three groups including the MEA+Alum i.p., MEA+Alum+CpG ODN i.p.and MEA+Quickantibody5W i.m.treatment groups were positive for IgA antibody .The highest titer of IgA antibody was detected in mice from the MEA+Alum+CpG ODN i.p.treatment group, which was 2.15×103.Compared with the control group, significantly enhanced proliferation of lymphocytes was observed in the MEA+Alum i.p., MEA+Alum+CpG ODN i.p.and MEA+Quickantibody5W i.m.treatment groups (P<0.05).Enhanced cytotoxic activities of CTL were observed in mice with ip.and i.m.treatments as compared with those in control group (P<0.05).The levels of CD4+/CD8+T cells were slightly increased in mice from the MEA+CpG ODN i.p., MEA+Alum+CpG ODN i.p. and MEA+Quickantibody5W i.m.treatment groups as compared with those in control group (P<0.05).In-creased secretion of IL-2, IFN-γand Th2-type cytokines including IL-4, IL-5 and IL-10 were detected in mice from the MEA+CpG ODN i.p.treatment group.The MEA+Alum i.p.treated mice showed a slightly increased secretion of IFN-γand significantly increased secretions of IL-4, IL-5 and IL-10.Significantly in-creased secretions of IFN-γ, IL-4, IL-5 and IL-10 were detected in mice from the MEA+Alum+CpG ODN i.p.treatment group.Significantly increased secretions of IFN-γ, IL-5, IL-10 and granulocyte-macrophage colony-stimulating factor (GM-CSF) were detected in mice from the MEA+Quickantibody5W i.m.treatment group.Conclusion MEA together with different adjuvants could stimulate high titers of specific antibodies , increase the proliferation of lymphocytes and enhance the cytotoxic activities of CTL .CpG ODN could bal-ance the Th1/Th2-mediated immune responses , and the balance could be enhanced when using CpG ODN in combination with Alum .A similar effect could be achieved by using the commercial adjuvant Quickanti -body5w.This study has paved the way for further investigation on the development of hMPV epitope vaccines and diagnostic reagents for hMPV as well as the epidemiological study of hMPV .
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Objective To understand the status of pertussis infection and characteristics of molecular epidemiology of pertussis in 2013 in Tianjin.Methods Totally,181 suspected pertussis cases were selected and their nasopharyngeal swabs and serum were sampled at the Disease Monitoring Settings in Tianjin.Real-time PCR was used to detect Bordetella pertussis double target genes and enzyme linked immune-sorbent assay (ELISA) method was used to detect the specific pertussis toxin IgG (PT-IgG) antibody.Fimbriae 2 (FIM2) and Fimbriae 3 (FIM3) genes of pertussis was amplified by PCR for sequencing,from 30 pertussis DNA positive samples.Results The positive rate of Real-time PCR was 68.24％ in 148 cases and the positive rate of PT-IgG antibody was 55.56％ in 108 cases.Among 101 cases that nucleic acid were positive,the median duration of disease was 11 days.Among the PT-IgG Positive cases (60 cases),the median duration of disease was 21 days.In cases under 1 year old,the Real-time PCR testing positive rate was 84.28％.Positive rates among other age groups,the differences were statistically significant.Nucleotide homologies of FIM2 and FIM3 genes from 30 pertussis strains were 99.6％-100.0％,while it was 99％ when compared to both international standard Tohama strain and Chinese vaccine strain.Conclusion Detection of pertussis by Real-time PCR from clinical nasopharyngeal swab sample was quick and sensitive for the diagnosis.Bordetella pertussis epidemic strains in Tianjin area appeared close relation with both the international standards and China vaccine strains.
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Objective To study proteome variation between uropathogenic E. coil (UPEC)132, UPEC J96 and non-uropathogenic E. coli K-12 MG1655. Methods Two-dimensional gel electrophoresis(2-DE) was applied to compare the differential expression proteins between UPEC 132, UPEC J96 and non-uro-pathogenic E.coli K-12 MG1655. The differential expression proteins were digested in gel by enzyme. The mass of generated peptides were measured by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). The data obtained from peptide mass fingerprinting (PMF) were re-searched using the internet available database. Results The number of protein spots recognized from UPEC 132 was 466±11, significantly more than that of E. coli K-12 MG1655 (338±15) and UPEC J96 (382±12); there were 298 protein spots shared by the three E.coli strains, 56 protein spots shared by two UPEC strains, and 89 protein spots characterized by UPEC 132. Twenty-two differential expression or significantly increased expression protein spots, involved in virulence factors, metabolism and transportation, regulation of protein synthesis, biological oxidation and unknown functions, were successfully identified by MALDI-TOF-MS. Condusion The proteome from UPEC 132 and non-uropathogenic E. coli K-12 MG1655, or UPEC 132 and UPEC J96 was differentially expressed. It will provide important information on the pathogen-esis of UPEC 132.